Effect of Land Use Changes on Soil Conditions in the Developed Areas: A Case of Kunshan in Jiangsu Province
经济发达区土地利用变化对土壤性质的影响 --以江苏省昆山市为例

In order to study soil property change in the rapid urbanization and industrialization process,6 typical land use patterns were chosen to study the effect of different land use patterns on soil nutrient,soil pollution and so on in Kunshan,Jiangsu province.We drew conclusions as follows:Firstly,it is clear of the effect of land use change on soil nutrient,soil pollution.Besides the available-K,land use change results in the increase of soil nutrient from 1981 to 2002.And the change extent of organic matter,total-N and available-N contents is different in different typical land use patterns,the order of organic matter contents in 2002 is paddy field>garden land>uncultivated land>vegetable land,the order of total-N and available-N contents is paddy field>garden land>vegetable land>uncultivated land,the order of available-K content is garden land>paddy field>uncultivated land> vegetable land,and the order of available-P content is uncultivated land>vegetable land>garden land>paddy field.Secondly,the variation coefficients of organic matter and total-N content are apparently higher than other soil nutrients,and the variation coefficient of total-N content is the highest.Thirdly,land use change impacts heavy metal concentration,the Hg,Cr,Ni and Cd contents in paddy field are higher than the background level,and the Hg,Ni and Cu contents are higher in vegetable land,heavy metal concentration is lower in garden land and uncultivated land,but Ni content in garden land and uncultivated land is at the same level with other typical land.Finally,the land economic coefficient correlates highly with soil nutrient and soil pollution.